This application claims the priority of German Application DE 199 47 6837, filed Oct. 5, 1999, and PCT/DE00/03478, filed Oct. 2, 2000, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a sound pressure level calibrator. The calibration of sound pressure level sensors is generally carried out with commercially available sound pressure level calibrators that can produce a maximum sound pressure of 94 dB or 124 dB. To measure sound pressure levels, calibration must be conducted with levels that are nearly as high as the levels to be measured in order to achieve the required measuring accuracy and to be able to check the required dynamics of the recording device of the measuring chain, e.g., a tape recorder, for optimum level control of the recording device. The sound pressure level of commercially available sound pressure level calibrators, which is limited in height, cannot always meet these requirements.
Furthermore, the sound pressure level calibrators of the prior art require the removal for calibration of the sound pressure level sensor from its supporting structure to adapt it to the commercially available sound pressure level calibrators. In prolonged measuring tests with frequent calibration processes, this required removal is very time-consuming and labor intensive. The frequent installation and removal also involves the risk that the sensitive sound pressure level sensor may be damaged.
The object of the invention is to provide a sound pressure level calibrator that is suitable for sound levels to be measured in excess of 124 dB and that can be adapted to the installed sound pressure level sensor.
The solution according to the invention is based on a high-pressure adapter on a commercially available pistonphone, which advantageously acoustically amplifies the sound pressure emitted by the pistonphone to values >150 dB and permits the in situ calibration of the sound pressure level sensor.
This makes it possible to conduct calibration in situ immediately prior to the start of the measuring process on the entire measuring chain and to take measurements with relatively high accuracy even if the sound pressure levels are high. In addition, the adapter advantageously permits the calibration of different sound pressure level sensors through adaptation modules.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.